1. Field of the Invention
The present invention relates to a power amplifier module.
2. Background Art
In a mobile communication device such as a mobile phone, a power amplifier module is used to amplify the power of a signal to be transmitted to a base station. Patent Document 1 discloses a configuration for variably controlling a power supply voltage supplied to a power amplification transistor in such a power amplifier module according to the level of required output power.
Patent Document 2 discloses a configuration for controlling a bias current in a power amplifier module. Specifically, in the configuration disclosed in Patent Document 2, when the peak value of collector voltage of a power amplification transistor becomes higher than a preset voltage due to a load variation, a bias circuit is controlled to increase the bias current.